fixes #670 MSVC x64 reports compiler warnings in efd.c
fixes #670 MSVC x64 reports compiler warnings in efd.c

snikulov/nanomsg,reqshark/nanomsg,thisco-de/nanomsg,reqshark/nanomsg,thisco-de/nanomsg,reqshark/nanomsg,featherweight/ftw-kernel-nanomsg,snikulov/nanomsg,featherweight/ftw-kernel-nanomsg